What are the recommended dosages for Attention Deficit Hyperactivity Disorder (ADHD) medications in pediatric patients?

ADHD Medication Dosing in Pediatric Patients

Age-Specific Treatment Approach

For preschool children (ages 4-5 years), behavior therapy should be the first-line treatment, with medication reserved only for those with moderate-to-severe dysfunction who have not responded adequately to behavioral interventions after at least 9 months of persistent symptoms. 1, 2

Preschool-Aged Children (4-5 years)

• When medication is necessary, methylphenidate should be initiated at lower starting doses with smaller incremental increases due to slower metabolism in this age group 1, 2
• Maximum doses have not been adequately studied in preschool-aged children, so caution is warranted 1
• Only children with dysfunction manifested in both home and other settings (preschool/child care) should be considered for medication 1

School-Aged Children (6 years and older)

Stimulant Medications (First-Line Treatment)

Methylphenidate:

• Starting dose: 5 mg twice daily (before breakfast and lunch) 3
• Titration: Increase by 5-10 mg weekly based on clinical response 3
• Maximum daily dose: 60 mg 3
• Dosing should not exceed 2 mg/kg/day 4

Amphetamine/Dextroamphetamine:

• Ages 3-5 years: Start with 2.5 mg daily; increase by 2.5 mg weekly 5
• Ages 6 years and older: Start with 5 mg once or twice daily; increase by 5 mg weekly 5
• Maximum daily dose: 40 mg 5, 2
• Rarely necessary to exceed 40 mg/day 5
• For children weighing less than 20 kg, use caution during titration 2

Lisdexamfetamine (Vyvanse):

• Titration requires 2-4 weeks to reach optimal dosing 6
• Weekly contact should be maintained during initial titration 6
• Maximum dose: 70 mg/day 2

Non-Stimulant Medications (Second-Line or When Stimulants Contraindicated)

Atomoxetine:

• Children/adolescents up to 70 kg: Start at 0.5 mg/kg/day; increase after minimum 3 days to target of 1.2 mg/kg/day 7
• Maximum: 1.4 mg/kg/day or 100 mg, whichever is less 7
• Children/adolescents over 70 kg: Start at 40 mg/day; increase after minimum 3 days to target of 80 mg 7
• May increase to maximum 100 mg after 2-4 additional weeks if optimal response not achieved 7
• Can be given as single morning dose or divided (morning and late afternoon/early evening) 7

Guanfacine Extended-Release:

• Target dose range: 0.05-0.12 mg/kg/day or 1-4 mg/day 2
• Maximum dose: 4 mg daily 2
• Titration: Increase by 1 mg increments weekly based on clinical response 2

Clonidine Extended-Release:

• Alternative non-stimulant option, particularly useful in adolescents with substance abuse concerns or medication diversion risk 1, 2

Adolescents (12-18 years)

Special Considerations

• Screen for substance use symptoms before initiating medication 1
• Monitor for medication diversion (use by parents, classmates, or acquaintances) 1
• Consider non-stimulant medications (atomoxetine, extended-release guanfacine, extended-release clonidine) to minimize abuse potential 1
• Provide medication coverage for driving hours using longer-acting or late-afternoon short-acting medications 1

Titration Protocol

Weekly dose adjustments are standard practice:

• Maintain weekly contact (telephone acceptable) during initial titration 6
• Assess clinical response and tolerability before each dose increase 6
• Use rating scales with age- and gender-specific norms to assess symptoms before treatment and after each major dose adjustment 1
• Systematically assess for side effects including insomnia, anorexia, headaches, weight loss, and mood changes 6

Monitoring Requirements

Growth Parameters

• Monitor weight at each visit to assess for appetite suppression 2, 6
• Closely monitor height and weight in pediatric patients, as long-term growth suppression can occur 3
• Growth attenuation is more pronounced in children requiring higher doses and those starting treatment at younger ages 4

Cardiovascular Monitoring

• Regularly assess blood pressure and pulse, especially at higher doses 2
• Avoid use in patients with known structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmias, coronary artery disease, or other serious cardiac disease 3

Psychiatric Monitoring

• Screen for personal or family history of bipolar disorder, mania, or hypomania before initiating treatment 7
• Monitor for emergence of psychotic or manic symptoms 3
• For atomoxetine specifically, monitor closely for suicidality, clinical worsening, and unusual behavioral changes 2

Special Dosing Adjustments

Hepatic Impairment (Atomoxetine)

• Moderate hepatic insufficiency (Child-Pugh Class B): Reduce initial and target doses to 50% of normal 7
• Severe hepatic insufficiency (Child-Pugh Class C): Reduce initial and target doses to 25% of normal 7

CYP2D6 Poor Metabolizers or Strong Inhibitor Use (Atomoxetine)

• Children/adolescents up to 70 kg: Start at 0.5 mg/kg/day; increase to 1.2 mg/kg/day only if symptoms fail to improve after 4 weeks and initial dose is well tolerated 7
• Children/adolescents over 70 kg and adults: Start at 40 mg/day; increase to 80 mg/day only if symptoms fail to improve after 4 weeks and initial dose is well tolerated 7

Common Pitfalls to Avoid

• Starting at too high a dose leads to unnecessary side effects and decreased medication adherence 6
• Failure to systematically assess both benefits and side effects during titration 6
• Not using standardized rating scales to objectively measure treatment response 1
• Administering late evening doses of stimulants, which causes insomnia 5
• Failing to screen for cardiac disease, bipolar disorder, or substance use before initiating treatment 1, 3, 7

Extended-Release Formulations

• Extended-release preparations provide 8-12 hours of symptom control with once-daily dosing 8, 9
• 8-hour preparations (Metadate CD, Ritalin LA) utilize microbead technology 8
• 12-hour preparation (Concerta) utilizes osmotic pump system 8
• All extended-release formulations are equally efficacious in controlling ADHD symptoms 9
• Capsule formulations can be opened and sprinkled on applesauce for patients with difficulty swallowing 9

Combination Treatment

• Behavioral therapy has positive effects when combined with medication for preadolescent children 1
• Combination therapy may be beneficial for patients with comorbid conditions, though medication alone is often sufficient for core ADHD symptoms 1